Mechanical behavior of Al–Si10–Mg gyroid surface with variable topological parameters fabricated via laser powder bed fusion

Abstract

Metallic cellular materials with triply periodic minimal surface (TPMS) topologies have great potential for lightweight and multi-functional applications. However, the effect of level-set values, which can control the topology of TPMS, on the performance of TPMS have not been fully understood because previous studies have mainly focused on the shell thickness, cell size and periodicity of TPMS. In this paper, Al–Si10–Mg gyroid surfaces with three different level-set values are fabricated by using selective laser melting (SLM). Micro computed tomography (Micro-CT) is used to reconstruct the 3D models of as-built samples, then the geometric deviations and surface quality are investigated. Mechanical behavior and energy absorption characteristics of these gyroid surfaces are investigated both experimentally and numerically, which provide a solid basis for predicting and controlling the deformation behavior in gyroid surfaces. Afterwards, the Gibson–Ashby model is used for understanding the effect of the level-set value on Young's modulus and plateau stress of gyroid surfaces. Finally, the relationship between level-set values and densification strain and energy absorbed per unit volume is also presented to gain insight into the role of level-set values on the energy absorption capability of the gyroid surfaces. Such understanding provides a new method to develop desired properties of implants or energy absorption applications by selecting an optimal combination of level-set value, thickness, periodicity etc.